Researchers at the South China University of Technology, Guangzhou, working with McMaster University, Ontario, have shown the effectiveness of commercial sunscreens can be enhanced by the addition of lignin. The study also showed sunlight exposure may even help sunscreens to work better.
Lignin is already known to be a useful UV-absorber and a broad-spectrum sun blocker, according to the researchers. However, although more than 50 million tons of lignin is produced industrially each year, it has never been used in sunscreens due to safety concerns.
Now that certain types of lignin have been found to be safe, the researchers experimented with adding 10wt% lignin into creams and evaluating their performance. When added to moisturiser, the lignin was found to increase the cream’s sunblock capability up to 5.72, outperforming a commercial SPF15 sunscreen. Adding it to a commercial SPF15 sunscreen gave a value of 89.58, far better than a commercial SPF50 product.
The performances of the sunscreens were also found to improve following UV irradiation, meaning the sunscreens could potentially improve their SPF values after sun exposure.
